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Zhang L, Luo H, Li C, Teng H, Powell B, Lu M, Chopp M, Zhang ZG. Treatment of stroke in aged male and female rats with Vepoloxamer and tPA reduces neurovascular damage. Front Neurol 2023; 14:1282736. [PMID: 37869138 PMCID: PMC10587547 DOI: 10.3389/fneur.2023.1282736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023] Open
Abstract
Stroke is a leading cause of death and disability worldwide, mainly affecting the elderly. Unfortunately, current treatments for acute ischemic stroke warrant improvement. To date, tissue plasminogen activator (tPA) is of limited use in stroke patients mainly due to its narrow therapeutic window and potential for hemorrhagic complication. The adjuvant treatment with Vepoloxamer, a purified amphipathic polymer has been shown to enhance the thrombolytic efficacy of tPA treatment in young adult male rats after embolic stroke. However, most stroke patients are aged; therefore, the current study investigated the therapeutic effect of the combined tPA and Vepoloxamer treatment in aged male and female rats subjected to embolic stroke. Methods Male and female Wistar rats at 18 months of age were subjected to embolic middle cerebral artery occlusion and treated either with monotherapy of tPA or Vepoloxamer, a combination of these two agents, or saline at 4 h after stroke onset. Neurological outcomes were evaluated with a battery of behavioral tests including adhesive removal, foot-fault, and modified neurological severity score tests at 1 and 7 days after stroke onset, followed by histopathological analysis of infarct volume. Residual clot size and vascular patency and integrity were analyzed. Results The combination treatment with Vepoloxamer and tPA significantly reduced infarct volume and neurological deficits in male and female rats compared to rats treated with saline and the monotherapies of tPA and Vepoloxamer. While Vepoloxamer monotherapy moderately reduced neurological deficits, monotherapies with tPA and Vepoloxamer failed to reduce infarct volume compared to saline treatment. Furthermore, the combination treatment with tPA and Vepoloxamer accelerated thrombolysis, reduced ischemia and tPA-potentiated microvascular disruption, and concomitantly improved cerebrovascular integrity and perfusion in the male ischemic rats. Conclusion Combination treatment with tPA and Vepoloxamer at 4 h after stroke onset effectively reduces ischemic neurovascular damage by accelerating thrombolysis and reducing ischemia and tPA potentiated side effects in the aged rats. This funding suggests that the combination treatment with tPA and Vepoloxamer represents a promising strategy to potentially apply to the general population of stroke patients.
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Affiliation(s)
- Li Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, MI, United States
| | - Hao Luo
- Department of Neurology, Henry Ford Hospital, Detroit, MI, United States
| | - Chao Li
- Department of Neurology, Henry Ford Hospital, Detroit, MI, United States
| | - Hua Teng
- Department of Neurology, Henry Ford Hospital, Detroit, MI, United States
| | - Brianna Powell
- Department of Neurology, Henry Ford Hospital, Detroit, MI, United States
| | - Mei Lu
- Department of Biostatistics and Research Epidemiology, Henry Ford Hospital, Detroit, MI, United States
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, MI, United States
- Department of Physics, Oakland University, Rochester, MI, United States
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, MI, United States
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Ye Y, Zhu YT, Tong HX, Han JY. The Protective Role of Immunomodulators on Tissue-Type Plasminogen Activator-Induced Hemorrhagic Transformation in Experimental Stroke: A Systematic Review and Meta-Analysis. Front Pharmacol 2020; 11:615166. [PMID: 33424615 PMCID: PMC7793743 DOI: 10.3389/fphar.2020.615166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/24/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Recanalization with tissue plasminogen activator (tPA) is the only approved agent available for acute ischemic stroke. But delayed treatment of tPA may lead to lethal intracerebral hemorrhagic transformation (HT). Numerous studies have reported that immunomodulators have good efficacy on tPA-induced HT in ischemic stroke models. The benefits of immunomodulators on tPA-associated HT are not clearly defined. Here, we sought to conduct a systematic review and meta-analysis of preclinical studies to further evaluate the efficacy of immunomodulators. Methods: The PubMed, Web of Science, and Scopus electronic databases were searched for studies. Studies that reported the efficacy of immunomodulators on tPA-induced HT in animal models of stroke were included. Animals were divided into two groups: immunomodulators plus tPA (intervention group) or tPA alone (control group). The primary outcome was intracerebral hemorrhage, and the secondary outcomes included infarct volume and neurobehavioral score. Study quality was assessed by the checklist of CAMARADES. We used standardized mean difference (SMD) to assess the impact of interventions. Regression analysis and subgroup analysis were performed to identify potential sources of heterogeneity and evaluate the impact of the study characteristics. The evidence of publication bias was evaluated using trim and fill method and Egger’s test. Results: We identified 22 studies that met our inclusion criteria involving 516 animals and 42 different comparisons. The median quality checklist score was seven of a possible 10 (interquartile range, 6–8). Immunomodulators improved cerebral hemorrhage (1.31 SMD, 1.09–1.52); infarct volume (1.35 SMD, 0.95–1.76), and neurobehavioral outcome (0.9 SMD, 0.67–1.13) in experimental stroke. Regression analysis and subgroup analysis indicated that control of temperature and time of assessment were important factors that influencing the efficacy of immunomodulators. Conclusion: Our findings suggested that immunomodulators had a favorable effect on tPA-associated intracerebral hemorrhage, cerebral infarction, and neurobehavioral impairments in animal models of ischemic stroke.
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Affiliation(s)
- Yang Ye
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, China.,Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
| | - Yu-Tian Zhu
- Department of Traditional Chinese Medicine, Peking University Third Hospital, Beijing, China.,Department of Urology, Peking University Third Hospital, Beijing, China
| | - Hong-Xuan Tong
- Institute of Basic Theory for Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jing-Yan Han
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, China.,Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
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Liu C, Xie J, Sun S, Li H, Li T, Jiang C, Chen X, Wang J, Le A, Wang J, Li Z, Wang J, Wang W. Hemorrhagic Transformation After Tissue Plasminogen Activator Treatment in Acute Ischemic Stroke. Cell Mol Neurobiol 2020; 42:621-646. [PMID: 33125600 DOI: 10.1007/s10571-020-00985-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/22/2020] [Indexed: 12/17/2022]
Abstract
Hemorrhagic transformation (HT) is a common complication after thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) in ischemic stroke. In this article, recent research progress of HT in vivo and in vitro studies was reviewed. We have discussed new potential mechanisms and possible experimental models of HT development, as well as possible biomarkers and treatment methods. Meanwhile, we compared and analyzed rodent models, large animal models and in vitro BBB models of HT, and the limitations of these models were discussed. The molecular mechanism of HT was investigated in terms of BBB disruption, rt-PA neurotoxicity and the effect of neuroinflammation, matrix metalloproteinases, reactive oxygen species. The clinical features to predict HT were represented including blood biomarkers and clinical factors. Recent progress in neuroprotective strategies to improve HT after stroke treated with rt-PA is outlined. Further efforts need to be made to reduce the risk of HT after rt-PA therapy and improve the clinical prognosis of patients with ischemic stroke.
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Affiliation(s)
- Chengli Liu
- Department of Traumatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Jie Xie
- Department of Traumatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Shanshan Sun
- Department of Ultrasound Imaging, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Hui Li
- Department of Traumatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Tianyu Li
- Department of Traumatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Chao Jiang
- Department of Neurology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, People's Republic of China
| | - Xuemei Chen
- Department of Anatomy, College of Basic Medical Sciences, Zhengzhou University, Henan, 450000, People's Republic of China
| | - Junmin Wang
- Department of Anatomy, College of Basic Medical Sciences, Zhengzhou University, Henan, 450000, People's Republic of China
| | - Anh Le
- Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Jiarui Wang
- The Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Zhanfei Li
- Department of Traumatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Jian Wang
- Department of Anatomy, College of Basic Medical Sciences, Zhengzhou University, Henan, 450000, People's Republic of China.
| | - Wei Wang
- Department of Traumatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
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Kim JS. tPA Helpers in the Treatment of Acute Ischemic Stroke: Are They Ready for Clinical Use? J Stroke 2019; 21:160-174. [PMID: 31161761 PMCID: PMC6549064 DOI: 10.5853/jos.2019.00584] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/15/2019] [Indexed: 12/12/2022] Open
Abstract
Tissue plasminogen activator (tPA) is the only therapeutic agent approved to treat patients with acute ischemic stroke. The clinical benefits of tPA manifest when the agent is administered within 4.5 hours of stroke onset. However, tPA administration, especially delayed administration, is associated with increased intracranial hemorrhage (ICH), hemorrhagic transformation (HT), and mortality. In the ischemic brain, vascular remodeling factors are upregulated and microvascular structures are destabilized. These factors disrupt the blood brain barrier (BBB). Delayed recanalization of the vessels in the presence of relatively matured infarction appears to damage the BBB, resulting in HT or ICH, also known as reperfusion injury. Moreover, tPA itself activates matrix metalloproteases, further aggravating BBB disruption. Therefore, attenuation of edema, HT, or ICH after tPA treatment is an important therapeutic strategy that may enable clinicians to extend therapeutic time and increase the probability of excellent outcomes. Recently, numerous agents with various mechanisms have been developed to interfere with various steps of ischemia/ reperfusion injuries or BBB destabilization. These agents successfully reduce infarct volume and decrease the incidence of ICH and HT after delayed tPA treatment in various animal stroke models. However, only some have entered into clinical trials; the results have been intriguing yet unsatisfactory. In this narrative review, I describe such drugs and discuss the problems and future directions. These “tPA helpers” may be clinically used in the future to increase the efficacy of tPA in patients with acute ischemic stroke.
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Affiliation(s)
- Jong S Kim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Keddy PGW, Dunlop K, Warford J, Samson ML, Jones QRD, Rupasinghe HPV, Robertson GS. Neuroprotective and anti-inflammatory effects of the flavonoid-enriched fraction AF4 in a mouse model of hypoxic-ischemic brain injury. PLoS One 2012; 7:e51324. [PMID: 23251498 PMCID: PMC3520852 DOI: 10.1371/journal.pone.0051324] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 10/31/2012] [Indexed: 11/23/2022] Open
Abstract
We report here neuroprotective and anti-inflammatory effects of a flavonoid-enriched fraction isolated from the peel of Northern Spy apples (AF4) in a mouse of model of hypoxic-ischemic (HI) brain damage. Oral administration of AF4 (50 mg/kg, once daily for 3 days) prior to 50 min of HI completely prevented motor performance deficits assessed 14 days later that were associated with marked reductions in neuronal cell loss in the dorsal hippocampus and striatum. Pre-treatment with AF4 (5, 10, 25 or 50 mg/kg, p.o.; once daily for 3 days) produced a dose-dependent reduction in HI-induced hippocampal and striatal neuron cell loss, with 25 mg/kg being the lowest dose that achieved maximal neuroprotection. Comparison of the effects of 1, 3 or 7 doses of AF4 (25 mg/kg; p.o.) prior to HI revealed that at least 3 doses of AF4 were required before HI to reduce neuronal cell loss in both the dorsal hippocampus and striatum. Quantitative RT-PCR measurements revealed that the neuroprotective effects of AF4 (25 mg/kg; p.o.; once daily for 3 days) in the dorsal hippocampus were associated with a suppression of HI-induced increases in the expression of IL-1β, TNF-α and IL-6. AF4 pre-treatment enhanced mRNA levels for pro-survival proteins such as X-linked inhibitor of apoptosis and erythropoietin following HI in the dorsal hippocampus and striatum, respectively. Primary cultures of mouse cortical neurons incubated with AF4 (1 µg/ml), but not the same concentrations of either quercetin or quercetin-3-O-glucose or its metabolites, were resistant to cell death induced by oxygen glucose deprivation. These findings suggest that the inhibition of HI-induced brain injury produced by AF4 likely involves a transcriptional mechanism resulting from the co-operative actions of various phenolics in this fraction which not only reduce the expression of pro-inflammatory mediators but also enhance pro-survival gene signalling.
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Affiliation(s)
- Paul G. W. Keddy
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kate Dunlop
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jordan Warford
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michel L. Samson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Quinton R. D. Jones
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - H. P. Vasantha Rupasinghe
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | - George S. Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Psychiatry, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Lapchak PA. Identifying Vascular Targets to Treat Hemorrhagic Stroke. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Harada K, Suzuki Y, Yamakawa K, Kawakami J, Umemura K. Combination of reactive oxygen species and tissue-type plasminogen activator enhances the induction of gelatinase B in brain endothelial cells. Int J Neurosci 2011; 122:53-9. [PMID: 21919816 DOI: 10.3109/00207454.2011.623808] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Tissue-type plasminogen activator (t-PA) increases the risk of intracranial hemorrhage by gelatinase B (matrix metalloprotease-9; MMP-9) production in brain endothelial cells. It was recently reported that the free-radical scavenger edaravone significantly decreases t-PA-mediated MMP-9 production. Therefore, by using cultured brain endothelial cells (b.End3), we investigated whether t-PA-mediated MMP-9 production was enhanced by reactive oxygen species (ROS) and its signaling pathways. Moreover, we also investigated that whether this combined enhancement is reduced by edaravone. The b.End3 cells were exposed to t-PA (10 μg/mL), followed by H2O2 (30 μM); further, the MMP-9 protein level was measured. ROS enhanced MMP-9 production, and ROS plus t-PA significantly increased MMP-9 production more than t-PA or ROS alone. The results showed that H2O2 or t-PA alone caused a significant increase in NF-κB translocation to the nucleus, whereas the combination of t-PA and H2O2 increased the translocation of NF-κB to an even greater extent. Moreover, the combination of t-PA and ROS significantly increased I-κB degradation as well as NF-κB expression. Edaravone completely decreased the ROS plus t-PA-mediated MMP-9 enhancement. In conclusion, ROS enhanced t-PA-mediated MMP-9 production in brain endothelial cells; this MMP-9 production was decreased by the addition of edaravone, which inhibited the NF-κB pathway, specifically by enhancing I-κB degradation.
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Affiliation(s)
- Kosuke Harada
- Department of Pharmacology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Lapchak PA, Wu Q. Vascular Dysfunction in Brain Hemorrhage: Translational Pathways to Developing New Treatments from Old Targets. JOURNAL OF NEUROLOGY & NEUROPHYSIOLOGY 2011; 2011:S1-e001. [PMID: 22400125 PMCID: PMC3293216 DOI: 10.4172/2155-9562.s1-e001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hemorrhagic stroke which is a form of stroke that affects 20% of all stroke patients is a devastating condition for which new treatments must be developed. Current treatment methods are quite insufficient to reduce long term morbidity and high mortality rate, up to 50%, associated with bleeding into critical brain structures, into ventricular spaces and within the subarachnoid space. During the last 10-15 years, significant advances in the understanding of important mechanisms that contribute to cell death and clinical deficits have been made. The most important observations revolve around a key set of basic mechanisms that are altered in brain bleeding models, including activation of membrane metalloproteinases, oxidative stress and both inflammatory and coagulation pathways. Moreover, it is now becoming apparent that brain hemorrhage can activate the ischemic stroke cascade in neurons, glial cells and the vascular compartment. The activation of multiple pathways allows comes the opportunity to intervene pharmacologically using monotherapy or combination therapy. Ultimately, combination therapy or pleiotropic compounds with multi-target activities should prove to be more efficacious than any single therapy alone. This article provides a comprehensive look at possible targets for small molecule intervention as well as some new approaches that result in metabolic down-regulation or inhibition of multiple pathways simultaneously.
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Affiliation(s)
- Paul A. Lapchak
- Director of Translational Research, Cedars-Sinai Medical Center, Department of Neurology, Davis Research Building, D- 2091, 110 N, George Burns Road, Los Angeles, CA 90048 USA
| | - Qiang Wu
- Project Scientist, Cedars-Sinai Medical Center, Department of Neurology, Davis Research Building, D-2094E, 110 N. George Burns Road, Los Angeles, CA 90048 USA
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Lapchak PA. A new embolus injection method to evaluate intracerebral hemorrhage in New Zealand white rabbits. Brain Res 2010; 1349:129-36. [PMID: 20599833 DOI: 10.1016/j.brainres.2010.06.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Revised: 06/11/2010] [Accepted: 06/14/2010] [Indexed: 01/01/2023]
Abstract
The rabbit large clot embolic stroke model has been used for over 23 years to study methods to manipulate hemorrhage and to test drugs and devices for safety, because the rabbit model is particularly sensitive to embolism-induced hemorrhage. This study refined the original embolization procedure using an automated, pump-assisted injection method to introduce large blood clots or macroscopic emboli into the middle cerebral artery (MCA) via an indwelling carotid artery catheter. The study shows that rapid injection of blood clots (3 ml/30s) produced a model where there is a high hemorrhage incidence rate (79%) and a high stroke success rate (63%), compared to a low stroke success rate (19%) with no hemorrhages when clots were injected at a slow rate (3 ml/90 s). The rapid injection method, which produces a high hemorrhage rate, is particularly useful to study neuroprotective agents to attenuate embolism-induced hemorrhage. In addition, we show that manual injection of blood clots, which produces a lower baseline hemorrhage rate (41%) with a similar stroke success rate (65%), may allow investigators to study pharmacological agents to either up or down-regulate hemorrhage incidence. Lastly, we show that in the rabbit embolic stroke model, hemorrhages are adjacent to areas of 2,3,5-triphenyltetrazolium (TTC)-negative tissue, normally associated with infarcted or ischemic tissue. Thus, there is clear separation of ischemia and hemorrhage in the model, suggesting that therapeutics that are neuroprotective may also be useful to limit the evolution of ischemic damage associated with a hemorrhage, if not attenuate hemorrhage itself.
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Affiliation(s)
- Paul A Lapchak
- Cedars-Sinai Medical Center, Department of Neurology, Burns & Allen Res. Inst. 110 North George Burns Road, D-2091, Los Angeles, CA 90048, USA.
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Lapchak PA, Han MK. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor simvastatin reduces thrombolytic-induced intracerebral hemorrhage in embolized rabbits. Brain Res 2009; 1303:144-50. [DOI: 10.1016/j.brainres.2009.09.064] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 09/12/2009] [Accepted: 09/15/2009] [Indexed: 10/20/2022]
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Lapchak PA, Han MK, Salgado KF, Streeter J, Zivin JA. Safety profile of transcranial near-infrared laser therapy administered in combination with thrombolytic therapy to embolized rabbits. Stroke 2008; 39:3073-8. [PMID: 18687999 DOI: 10.1161/strokeaha.108.516393] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE Transcranial near-infrared laser therapy (TLT) is currently under investigation in a pivotal clinical trial that excludes thrombolytic therapy. To determine if combining tissue plasminogen activator (tPA; Alteplase) and TLT is safe, this study assessed the safety profile of TLT administered alone and in combination with Alteplase. The purpose for this study is to determine if the combination of TLT and thrombolysis should be investigated further in a human clinical trial. METHODS We determined whether postembolization treatment with TLT in the absence or presence of tPA would affect measures of hemorrhage or survival after large clot embolism-induced strokes in New Zealand white rabbits. RESULTS TLT did not significantly alter hemorrhage incidence after embolization, but there was a trend for a modest reduction of hemorrhage volume (by 65%) in the TLT-treated group compared with controls. Intravenous administration of tPA, using an optimized dosing regimen, significantly increased hemorrhage incidence by 160%. The tPA-induced increase in hemorrhage incidence was not significantly affected by TLT, although there was a 30% decrease in hemorrhage incidence in combination-treated rabbits. There was no effect of TLT on hemorrhage volume measured in tPA-treated rabbits and no effect of any treatment on 24-hour survival rate. CONCLUSIONS In the embolism model, TLT administration did not affect the tPA-induced increase in hemorrhage incidence. TLT may be administered safely either alone or in combination with tPA because neither treatment affected hemorrhage incidence or volume. Our results support the study of TLT in combination with Alteplase in patients with stroke.
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Affiliation(s)
- Paul A Lapchak
- Department of Neuroscience, University of California San Diego, La Jolla, CA 92093-0624, USA.
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